To facilitate the automatic sorting and routing of the mail, U.S. Postal regulations allow shippers to enjoy a postage discount if they pre-print the appropriate bar codes on the outgoing mail. One type of bar code is known in the trade as Postnet bar code, which if desired may be used to encode ZIP code information.
The United States Postal Service (USPS) has been using the Postnet bar code for years to facilitate the automatic sorting and routing or mail pieces in the main facilities around the country.
Numerous products that generate and print Postnet bar codes on mail based on the ZIP code have been designed and co-sponsored by USPS. It is presently being claimed that by the year 1995, more than 95% of U.S. mail will carry on such a bar code.
Before the application of such bar code, over 17 people per sorting station could be needed to manually sort and route mail. Regardless of the high missorting rate, it was considered one of the most tedious and labor intensive processes at postal sorting facilities. Since the introduction of Postnet bar codes, the sorting and routing efficiency has been brought up many magnitudes over the manual process. Many stations can process as many as 37,000 pieces per hour with only two people.
Postage regulations dictate the size, configuration, location of the Postnet code on mail. This is to allow prior art apparatuses (such as those believed to be in current use by the USPS) to easily read the code, especially as location and orientation of the code is known. However, such prior art apparatuses are ineffective if the location and angular orientation of the Postnet code is not a constant, but instead random.
As it is anticipated that the Postnet bar code may become more universally accepted for use in packaging and other mailings, and it is anticipated that the code may be so used in a less universal manner, such as being randomly applied to the side of a package. Therefore a need has been recognized to provide a Postnet bar code reading system which recognizes randomly oriented Postnet bar codes, unlike current prior art systems which rely upon consistent location and alignment of the bar code to facilitate reading.